The present invention relates to expandable and collapsible structures and, more particularly, to such structures including split scissor assemblies.
My prior U.S. Pat. Nos. 6,141,934, 5,651,228, 5,444,946, 5,274,980, 5,230,196, RE33,710, U.S. Pat. Nos. 4,970,841, 4,838,003, 4,800,663, 4,761,929, 4,747,239, 4,689,932, 4,666,102, 4,637,180, 4,579,066, 4,561,618, 4,522,008, 4,512,097, 4,473,986, 4,437,275, 4,334,660, 4,290,244, 4,280,521, 4,026,313, and 3,968,808 are incorporated by reference and show various collapsible structures and components therefore. Many collapsible structures have sloped side walls. These sloped side walls can be disadvantageous because they do not permit usage of all of the space within the structure, particularly near bottom corners of the structure. Also, these structures do not “complex” or arrange adjacent to one another in a connected fashion as structures having vertical walls which can be connected to one another to form larger structures.
My U.S. Pat. No. 5,230,196 discloses one approach to providing collapsible structures with substantially vertical walls. In structures made according to this patent, interconnected modules form a dome or peak using struts that are joined to one another in a scissor-like manner with pivot pins located at points offset from the longitudinal centers of the struts. The amount of rise that is achieved by a given module depends upon where the struts are joined to one another. One shortcoming of structures where struts are joined off-center is that it can be difficult to arrange the struts so that the structure can be conveniently folded.
My U.S. Pat. No. 5,274,980 discloses a solution to the problem of off-center joining of struts and provides a module including a split scissor. To facilitate folding, at least one strut of the scissor is telescopic. The telescopic strut adds a degree of complexity to the structure.
My U.S. Pat. No. 6,141,934 discloses yet another structure. In this structure, modules are not only formed with struts that intersect one another at points remote from the longitudinal centers of the struts, the modules are pivotably connected to vertical leg members at an upper side of the module and are supported by a telescoping member. This structure is also somewhat complex.
It is desirable to provide an expandable and collapsible structure that includes a plurality of interconnected modules that can be arranged relative to one another to form a peaked structure. It is also desirable to provide an expandable and collapsible structure having vertical side walls.
In accordance with an aspect of the present invention, an expandable and collapsible scissor assembly for an expandable and collapsible structure includes a first strut having a first end and a second end. The assembly also includes a second strut upper portion having a first end and a second end, the first end of the second strut upper portion being pivotably connected to the first strut at an upper strut connection point, and a second strut lower portion having a first end and a second end, the second end of the second strut lower portion being pivotably connected to the first strut at a lower strut connection point. The lower strut connection point is between the upper strut connection point and the first end of the first strut and the scissor assembly is movable between a folded position in which the first end of the first strut and the second end of the second strut upper portion are substantially adjacent and the second end of the first strut and the first end of the second strut lower portion are substantially adjacent, and an expanded position.
In accordance with another aspect of the present invention, an expandable and collapsible structural module is provided. The module includes a left and a right split scissor assembly, each split scissor assembly including a first strut having a first end and a second end, a second strut upper portion having a first end and a second end, the first end of the second strut upper portion being pivotably connected to the first strut at an upper strut connection point, a second strut lower portion having a first end and a second end, the second end of the second strut lower portion being pivotably connected to the first strut at a lower strut connection point, wherein the lower strut connection point is between the upper strut connection point and the first end of the first strut. The module also includes a front and a back scissor assembly, each scissor assembly including a first scissor strut and a second scissor strut, the front and back first scissor struts each having a first end connected to the second end of the left second strut upper portion and the first end of the left first strut, respectively, and a second end connected to the second end of the right first strut and the first end of the right second strut lower portion, respectively, and the front and back second scissor struts each having a first end connected to the second end of the left first strut and the first end of the left second strut lower portion, respectively, and a second end connected to the second end of the right second strut upper portion and the first end of the right first strut, respectively.
In accordance with still another aspect of the present invention, an expandable and collapsible structure is provided. The structure includes a plurality of expandable and collapsible structural modules. Each module includes a left and a right split scissor assembly, each split scissor assembly including a first strut having a first end and a second end. Each module also includes a second strut upper portion having a first end and a second end, the first end of the second strut upper portion being pivotably connected to the first strut at an upper strut connection point, and a second strut lower portion having a first end and a second end, the second end of the second strut lower portion being pivotably connected to the first strut at a lower strut connection point. The lower strut connection point is between the upper strut connection point and the first end of the first strut. Each module also includes a front and a back scissor assembly. Each scissor assembly includes a first scissor strut and a second scissor strut, the front and back first scissor struts each having a first end connected to the second end of the left second strut upper portion and the first end of the left first strut, respectively, and a second end connected to the second end of the right first strut and the first end of the right second strut lower portion, respectively. The front and back second scissor struts each have a first end connected to the second end of the left first strut and the first end of the left second strut lower portion, respectively, and a second end connected to the second end of the right second strut upper portion and the first end of the right first strut. For at least one pair of the modules, the modules are connected to one another in that a second end of a second strut upper portion and a second end of a first strut of a left split scissor assembly of one module is connected to a second strut upper portion and a second end of a first strut of a right split scissor assembly of another module.
In accordance with still another aspect of the present invention, an expandable and collapsible structural module is provided. The module includes a left and a front split scissor assembly, each split scissor assembly including a first strut having a first end and a second end, a second strut upper portion having a first end and a second end, the first end of the second strut upper portion being pivotably connected to the first strut at an upper strut connection point, a second strut lower portion having a first end and a second end, the second end of the second strut lower portion being pivotably connected to the first strut at a lower strut connection point, wherein the lower strut connection point is between the upper strut connection point and the first end of the first strut. Each modules also includes a right and a back scissor assembly, each scissor assembly including a first scissor strut and a second scissor strut, the right and back first scissor struts each having a first end connected to the second end of the left second strut upper portion and the first end of the left first strut, respectively, and a second end connected to the second end of the front first strut and the first end of the front second strut lower portion, respectively, and the right and back second scissor struts each having a first end connected to the second end of the left first strut and the first end of the left second strut lower portion, respectively, and a second end connected to the second end of the front second strut upper portion and the first end of the front first strut.